Noise pollution is certainly annoying, but does it actually cause any real harm? Several studies have shown that urban noise can have adverse effects on bird populations, causing them to change their songs and otherwise alter their behavior. Now researchers have learned that man-made noise can also have a ripple effect on some types of plants, like trees, as well. Because plants are stationary, many of them rely on animals and insects, like birds and bees, to pollinate them or to spread their seeds. So it follows that when bird populations are driven down by noisy human activity, for example, the trees that depend on those birds to spread their seed would also suffer.

For the study, which appeared in a recent issue of the journal Proceedings of the Royal Society B, researchers conducted a series of experiments at the Rattlesnake Canyon Wildlife Area in northwestern New Mexico, which is filled with thousands of natural gas wells. The wells and the accompanying compressors, which are used to extract the gas and pump it through pipelines, produce a loud rumble all day, every day. So unlike an urban environment, which possesses a number of stimuli that might drive wildlife away (bright lights, buildings, traffic, etc.), the only real influence in Rattlesnake Canyon is the sound of the gas wells.

To test out how the noise affects birds in the area, researchers ran a couple of tests and found that noise may indirectly benefit some plants. One species of plant that experienced adverse effects of man-made noise was piñon pine, a very common tree in northwest New Mexico. Seedlings at quiet sites were four times more abundant than at noisy ones. The team attributes this to differences in the animals picking up the seeds. The western scrub jay, which tends to avoid noisy areas, can take hundreds or even thousands of piñon pine seeds and hide them to eat later. As a result, researchers found that piñon pine seedlings were four times as abundant in quiet sites they were in noisy ones.